OBJECTIVES We sought to demonstrate the mode of spontaneous onset of ventricular fibrillation (VF) in patients with Brugada syndrome. BACKGROUND The electrophysiologic mechanisms of VF in Brugada syndrome have not been fully investigated. METHODS Nineteen patients (all male, mean age 47 +/- 12 years) with Brugada syndrome were treated with an implantable cardioverter defibrillator (ICD). Th...

It is unknown whether ventricular fibrillation (VF) studied in experimental models represents in vivo human VF. First, we examined closed chest in vivo VF induced at defibrillation threshold testing (DFT) in four patients with ischemic cardiomyopathy pretransplantation. We examined VF in these same four hearts in an ex vivo human Langendorff posttransplantation. VF from DFT was compared with VF...

OBJECTIVES This multicenter study sought to evaluate the long-term follow-up of patients ablated for idiopathic ventricular fibrillation (VF). BACKGROUND Catheter ablation of idiopathic VF that targets ventricular premature beat (VPB) triggers has been shown to prevent VF recurrences on short-term follow-up. METHODS From January 2000, 38 consecutive patients from 6 different centers underwe...

OBJECTIVE To compare the occurrence of normal visual field (VF) test results following 2 vs 3 consecutive, abnormal, reliable test results in the Ocular Hypertension Treatment Study. METHODS The Ocular Hypertension Treatment Study is a prospective, multicenter follow-up study as part of a longitudinal randomized clinical trial. Sixty-four (68 eyes) of 1636 participants developed a VF primary ...

BACKGROUND Shocks that have defibrillated spontaneous ventricular fibrillation (VF) during acute ischemia or reperfusion may seem to have failed if VF recurs before the ECG amplifier recovers after shock. This could explain why the defibrillation threshold (DFT) for spontaneous VF appears markedly higher than for electrically induced VF. METHODS AND RESULTS The DFT for electrically induced VF...

Background—A therapeutic implication of the focal-source hypothesis of ventricular fibrillation (VF) is that VF can be terminated by focal ablation. We hypothesize that -adrenergic receptor blockade converts multiple-wavelet VF to focal-source VF and that this focal source is located near the papillary muscle (PM). Methods and Results—We used optical mapping techniques to study the effects of p...

The cellular events during the initiation and maintenance of ventricular fibrillation (VF) are poorly understood. We developed a nonischemic, isolated, perfused rabbit Langendorff preparation in which sustained VF could be induced by alternating current (AC) and which allowed changes in perfusate composition. We also used Na(+)-K+ pump inhibition (10 microM ouabain or K(+)-free perfusate) to in...

BACKGROUND Catheter ablation is an effective therapy for ventricular fibrillation (VF) arising from the Purkinje system in ischemic heart disease. However, some patients experience newly emergent monomorphic ventricular tachycardia (VT) after the ablation of VF. We evaluated the prevalence and mechanism of monomorphic VT after VF ablation. METHODS AND RESULTS Twenty-one consecutive patients w...

The mechanisms responsible for the maintenance and termination of ventricular fibrillation (VF) are poorly understood. The aim of this study was to compare the spectral characteristics of the electrical signal during sustained and non-sustained VF in patients with an implantable cardioverter-defibrillator. The study included 51 patients who had had at least one episode of sustained VF (i.e., du...

BACKGROUND There has been recent interest in the importance of visceral fat (VF) for the development of atherosclerosis. The purpose of this study was to examine associations between VF and multiple risk factors as well as the prevalence of carotid atherosclerosis in chronic haemodialysis patients. METHODS We classified 77 non-diabetic haemodialysis patients into 'low VF', 'middle VF' and 'hi...